They're actually just inactive accounts, I was one of those inactive accounts for a couple of months just logging in to get daily login reward and not do anything else. Naturally I only got 0 points on the on going events and tournaments in my groups.

There's actually more inactive accounts than active ones in this game

Over 99% completely quit at an early stage so not just inactive.

Im an inactive now, i do my cb keys and chat a bit but thats it, so i guess i will show on those tournaments too.

I'm an active player and my score in the actual Fire Knight tournament is still 0. I don't need Stun sets right now and spent my energy for other parts of the game.

Players are enlisted for the tournaments automatically, you will allways have some players with a rating of 0, that are not interested in the actual tournament.

I think a lot of people just don't pay attention to tournements, or don't care unless they need FK artifacts.  

For example, I have a booster active so I'm farming XP instead, more valuable for me at the moment to spend my energy there.  Otherwise, I would focus on FK for the rewards.

I confirm that these accounts are not bots, but just some inactive players